lm317 universal battery charger circuit


Posted on Feb 5, 2014

This universal battery charger is based on LM317 and has an adjustable regulated output voltage and also has an adjustable constant-current charging circuit that makes it suitable to use for charging most NiCad batteries and some other types of batteries. This LM317 universal battery charger can charge a single cell or a number of series-connecte


lm317 universal battery charger circuit
Click here to download the full size of the above Circuit.

d cells up to a maximum voltage of 18 V. This universal battery charger circuit use just some common electronic components like LM317 regulator, operational amplifier and some 2n3055 power transistors. 2n3055 power transistors Q1 and Q2 are connected as series regulators to control the battery charger`s out ¬put voltage and charge-current rate. The LM317 used as an adjustable voltage regulator supplies the drive signal to the bases of power transistors Q1 and Q2. By turning the potentiometer R9 the output-voltage level will be modified. A current-sampling resistor, R8 (a 0. 1-fi, 5-W unit), connected between the negative output lead and circuit ground. As the charging voltage across the battery begins to drop, the current through R8 decreases, then the voltage feeding pin 5 of U3 decreases, and the comparator output follows, turning Q3 back off, which completes the signal`s circular path to regulate the battery`s charging current.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Remote control (IR) Tester
    200 LEDs Christmas Lights circuit
    Op Amp Power Driver
    Driving a servo with MOSFET
    Speech Filter
    Simple Active Mixer on sinlge voltage
    Electrical Systems and Circuits
    555 IC Square Wave Oscillator circuit
    Using voice switch circuit relay lighting



    Top